1. Field of the Invention
The present invention relates to a liquid crystal display device and a method for manufacturing the liquid crystal display device.
2. Description of the Related Art
As a display device which is thin and lightweight (a so-called flat-panel display), a liquid crystal display device including a liquid crystal element, a light-emitting device including a self-light-emitting element, a field emission display (an FED), and the like have been competitively developed.
In a liquid crystal display device, response speed of liquid crystal molecules is required to be increased. Among various kinds of display modes of a liquid crystal, a ferroelectric liquid crystal (FLC) mode, an optical compensated bend (OCB) mode, and a mode using a liquid crystal exhibiting a blue phase can be given as liquid crystal modes by which high-speed response is possible.
The blue phase is a liquid crystal phase which appears between a chiral nematic phase having a relatively short spiral pitch and an isotropic phase, and has a characteristic of an extremely high response speed. In addition, when the blue phase is used, an alignment film is not required, and a wide viewing angle is provided; therefore, the blue phase has been developed for practical use. However, the blue phase is exhibited only in a small temperature range of 1° C. to 3° C. between a cholesteric phase and an isotropic phase. Thus, there is a problem in that the temperature of the element needs to be controlled precisely.
In order to solve this problem, it is proposed that the temperature range of exhibiting the blue phase be widened by performing polymer stabilization treatment (see Patent Document 1, for example).